A toddler was clinging to life last night after he accidentally fell out of a window of his family’s Bronx apartment building, cops said.

The three-year-old boy, who was not identified, tumbled out of the fourth floor window at 250 East 176th St. in the Tremont section just before 1 p.m. yesterday. The child was taken to St. Barnabus Hospital, but later transferred to Columbia Presbyterian.